<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="en-US">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=11"/>
<meta name="generator" content="Doxygen 1.9.8"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>libcoap: coap_hashkey.c Source File</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<link href="navtree.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="resize.js"></script>
<script type="text/javascript" src="navtreedata.js"></script>
<script type="text/javascript" src="navtree.js"></script>
<link href="search/search.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="search/searchdata.js"></script>
<script type="text/javascript" src="search/search.js"></script>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
 <tbody>
 <tr id="projectrow">
  <td id="projectalign">
   <div id="projectname">libcoap<span id="projectnumber">&#160;4.2.0</span>
   </div>
  </td>
 </tr>
 </tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.9.8 -->
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
var searchBox = new SearchBox("searchBox", "search/",'.html');
/* @license-end */
</script>
<script type="text/javascript" src="menudata.js"></script>
<script type="text/javascript" src="menu.js"></script>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
$(function() {
  initMenu('',true,false,'search.php','Search');
  $(document).ready(function() { init_search(); });
});
/* @license-end */
</script>
<div id="main-nav"></div>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
$(document).ready(function() { init_codefold(0); });
/* @license-end */
</script>
</div><!-- top -->
<div id="side-nav" class="ui-resizable side-nav-resizable">
  <div id="nav-tree">
    <div id="nav-tree-contents">
      <div id="nav-sync" class="sync"></div>
    </div>
  </div>
  <div id="splitbar" style="-moz-user-select:none;" 
       class="ui-resizable-handle">
  </div>
</div>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:d3d9a9a6595521f9666a5e94cc830dab83b65699&amp;dn=expat.txt MIT */
$(document).ready(function(){initNavTree('coap__hashkey_8c_source.html',''); initResizable(); });
/* @license-end */
</script>
<div id="doc-content">
<!-- window showing the filter options -->
<div id="MSearchSelectWindow"
     onmouseover="return searchBox.OnSearchSelectShow()"
     onmouseout="return searchBox.OnSearchSelectHide()"
     onkeydown="return searchBox.OnSearchSelectKey(event)">
</div>

<!-- iframe showing the search results (closed by default) -->
<div id="MSearchResultsWindow">
<div id="MSearchResults">
<div class="SRPage">
<div id="SRIndex">
<div id="SRResults"></div>
<div class="SRStatus" id="Loading">Loading...</div>
<div class="SRStatus" id="Searching">Searching...</div>
<div class="SRStatus" id="NoMatches">No Matches</div>
</div>
</div>
</div>
</div>

<div class="header">
  <div class="headertitle"><div class="title">coap_hashkey.c</div></div>
</div><!--header-->
<div class="contents">
<a href="coap__hashkey_8c.html">Go to the documentation of this file.</a><div class="fragment"><div class="line"><a id="l00001" name="l00001"></a><span class="lineno">    1</span><span class="comment">/* coap_hashkey.c -- definition of hash key type and helper functions</span></div>
<div class="line"><a id="l00002" name="l00002"></a><span class="lineno">    2</span><span class="comment"> *</span></div>
<div class="line"><a id="l00003" name="l00003"></a><span class="lineno">    3</span><span class="comment"> * Copyright (C) 2010,2011 Olaf Bergmann &lt;bergmann@tzi.org&gt;</span></div>
<div class="line"><a id="l00004" name="l00004"></a><span class="lineno">    4</span><span class="comment"> *</span></div>
<div class="line"><a id="l00005" name="l00005"></a><span class="lineno">    5</span><span class="comment"> * This file is part of the CoAP library libcoap. Please see</span></div>
<div class="line"><a id="l00006" name="l00006"></a><span class="lineno">    6</span><span class="comment"> * README for terms of use.</span></div>
<div class="line"><a id="l00007" name="l00007"></a><span class="lineno">    7</span><span class="comment"> */</span></div>
<div class="line"><a id="l00008" name="l00008"></a><span class="lineno">    8</span> </div>
<div class="line"><a id="l00009" name="l00009"></a><span class="lineno">    9</span><span class="preprocessor">#include &quot;<a class="code" href="coap__hashkey_8h.html">coap_hashkey.h</a>&quot;</span></div>
<div class="line"><a id="l00010" name="l00010"></a><span class="lineno">   10</span> </div>
<div class="line"><a id="l00011" name="l00011"></a><span class="lineno">   11</span><span class="keywordtype">void</span></div>
<div class="foldopen" id="foldopen00012" data-start="{" data-end="}">
<div class="line"><a id="l00012" name="l00012"></a><span class="lineno"><a class="line" href="coap__hashkey_8c.html#a1f8fb366d21f56f2e619c42a516114f6">   12</a></span><a class="code hl_function" href="coap__hashkey_8c.html#a1f8fb366d21f56f2e619c42a516114f6">coap_hash_impl</a>(<span class="keyword">const</span> <span class="keywordtype">unsigned</span> <span class="keywordtype">char</span> *s, <span class="keywordtype">unsigned</span> <span class="keywordtype">int</span> len, <a class="code hl_typedef" href="coap__hashkey_8h.html#a14b49ce1f8be4059e84df8e9d2a19586">coap_key_t</a> h) {</div>
<div class="line"><a id="l00013" name="l00013"></a><span class="lineno">   13</span>  <span class="keywordtype">size_t</span> j;</div>
<div class="line"><a id="l00014" name="l00014"></a><span class="lineno">   14</span> </div>
<div class="line"><a id="l00015" name="l00015"></a><span class="lineno">   15</span>  <span class="keywordflow">while</span> (len--) {</div>
<div class="line"><a id="l00016" name="l00016"></a><span class="lineno">   16</span>    j = <span class="keyword">sizeof</span>(<a class="code hl_typedef" href="coap__hashkey_8h.html#a14b49ce1f8be4059e84df8e9d2a19586">coap_key_t</a>)-1;</div>
<div class="line"><a id="l00017" name="l00017"></a><span class="lineno">   17</span> </div>
<div class="line"><a id="l00018" name="l00018"></a><span class="lineno">   18</span>    <span class="keywordflow">while</span> (j) {</div>
<div class="line"><a id="l00019" name="l00019"></a><span class="lineno">   19</span>      h[j] = ((h[j] &lt;&lt; 7) | (h[j-1] &gt;&gt; 1)) + h[j];</div>
<div class="line"><a id="l00020" name="l00020"></a><span class="lineno">   20</span>      --j;</div>
<div class="line"><a id="l00021" name="l00021"></a><span class="lineno">   21</span>    }</div>
<div class="line"><a id="l00022" name="l00022"></a><span class="lineno">   22</span> </div>
<div class="line"><a id="l00023" name="l00023"></a><span class="lineno">   23</span>    h[0] = (h[0] &lt;&lt; 7) + h[0] + *s++;</div>
<div class="line"><a id="l00024" name="l00024"></a><span class="lineno">   24</span>  }</div>
<div class="line"><a id="l00025" name="l00025"></a><span class="lineno">   25</span>}</div>
</div>
<div class="line"><a id="l00026" name="l00026"></a><span class="lineno">   26</span> </div>
<div class="ttc" id="acoap__hashkey_8c_html_a1f8fb366d21f56f2e619c42a516114f6"><div class="ttname"><a href="coap__hashkey_8c.html#a1f8fb366d21f56f2e619c42a516114f6">coap_hash_impl</a></div><div class="ttdeci">void coap_hash_impl(const unsigned char *s, unsigned int len, coap_key_t h)</div><div class="ttdoc">Calculates a fast hash over the given string s of length len and stores the result into h.</div><div class="ttdef"><b>Definition</b> <a href="coap__hashkey_8c_source.html#l00012">coap_hashkey.c:12</a></div></div>
<div class="ttc" id="acoap__hashkey_8h_html"><div class="ttname"><a href="coap__hashkey_8h.html">coap_hashkey.h</a></div><div class="ttdoc">definition of hash key type and helper functions</div></div>
<div class="ttc" id="acoap__hashkey_8h_html_a14b49ce1f8be4059e84df8e9d2a19586"><div class="ttname"><a href="coap__hashkey_8h.html#a14b49ce1f8be4059e84df8e9d2a19586">coap_key_t</a></div><div class="ttdeci">unsigned char coap_key_t[4]</div><div class="ttdef"><b>Definition</b> <a href="coap__hashkey_8h_source.html#l00022">coap_hashkey.h:22</a></div></div>
</div><!-- fragment --></div><!-- contents -->
</div><!-- doc-content -->
<!-- start footer part -->
<div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
  <ul>
    <li class="navelem"><a class="el" href="dir_68267d1309a1af8e8297ef4c3efbcdba.html">src</a></li><li class="navelem"><a class="el" href="coap__hashkey_8c.html">coap_hashkey.c</a></li>
    <li class="footer">Generated on Fri Dec 27 2024 09:57:44 for libcoap by <a href="https://www.doxygen.org/index.html"><img class="footer" src="doxygen.svg" width="104" height="31" alt="doxygen"/></a> 1.9.8 </li>
  </ul>
</div>
</body>
</html>
